Re: not cool enough
If you switch off a thermostat on a self defroster it wont cycle back on immediately until temperture rises to its normal switch back on temp,it’s because of the wider differential, these stats are set to so they allow the defrost to take place.
It is bad practice to switch off and then straight back on again,because,the compressor builds up pressure in order to effect refigeration, by switching straight back on the system pressure cant equalize so you are asking the compressor to start against the pressure causing overload which can cause the motor protector to operate.Domestic system don’t generally use capoacitor assisted start relays so dont cope well with switching on and off.
It,s programmed in to most electronic controlled ones so that they always delay compressor start to aloow the equalisation of the system pressure.
KW is correct,difficult to be accurate when not hands on but sounds past repair.
BG